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Disc brake rubbing question

roadrunner20roadrunner20 Posts: 40
in Workshop
Hey all.

Bike in question is canyon aeroad with ultegra discs.

Issue is disc brakes are rubbing when I'm climbing or sprinting, also I sometimes get rub after a decent.

I have centered the disc brakes few times but climbs and sprints they always rub, is this normal? Never really had issue with V brakes on old bike but know disc brake tolerances are small.


Options, bar your advice... Lol.
1: re centre again so wheel off pistons cleaned and reset, cardboard shim attached, wheel on, recentre brakes.

Bar this no other ideas.

Cheers all

Posts

  • oxomanoxoman Posts: 11,724
    Are your axles / QR tight as once everything set up nothing should move. Never had to recentre on my disc bike with axles but have had to on one with QR,s
    Too many bikes according to Mrs O.
  • ibr17xviiibr17xvii Posts: 1,065
    Deffo clean & regrease your pistons.

    I have a Canyon Endurace & mine does this (posted on here a few times about it) & cleaning the pistons usually solves it.

    Occurs again after a few months but to be fair it is my winter bike so does get some abuse.
  • daviescgwendaviescgwen Posts: 44
    Have you checked to if one of the pistons is sticking slightly?
    Dust from the pads can sometimes cause one side to retract more slowly.
    Have a look at this it may help:

    https://m.youtube.com/watch?v=LYExdy_yn3A
  • roadrunner20roadrunner20 Posts: 40
    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all?

    I think personally it could be the pistons like you suggested, with regards to cleaning them can you use disc brake cleaner? (or am I going to have to go and buy a load of shimano disc brake fluid?)

    Cheers again
  • oxomanoxoman Posts: 11,724
    No they shouldn't. Nothing should really move, you may get some flex but not next to the axles. You can try brake cleaner. Shimano disc brake fluid is for in the calipers and levers
    Too many bikes according to Mrs O.
  • ibr17xviiibr17xvii Posts: 1,065
    roadrunner20 said:

    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all?

    I think personally it could be the pistons like you suggested, with regards to cleaning them can you use disc brake cleaner? (or am I going to have to go and buy a load of shimano disc brake fluid?)

    Cheers again

    Isopropyl alcohol does the job for cleaning & is pretty inexpensive.

    I use the mineral oil to regrease the pistons but the jury seems to be out on whether that's necessary or not.
  • Charlie_CrokerCharlie_Croker Posts: 1,660
    roadrunner20 said:

    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all

    Ideally they should not ‘rub’ and I cannot see why they would, but they may touch if you are throwing the bike around a bit, you say it happens when you climb or sprint (sideways bike movement), I’m assuming you do both of these out of the saddle? Wheels do flex quite a lot. Even though the disc is attached to the hub there may be some movement
  • ibr17xviiibr17xvii Posts: 1,065
    roadrunner20 said:

    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all?

    I think personally it could be the pistons like you suggested, with regards to cleaning them can you use disc brake cleaner? (or am I going to have to go and buy a load of shimano disc brake fluid?)

    Cheers again

    Plenty of good stuff on this thread I posted on the very same topic:

    https://forum.bikeradar.com/discussion/13107944/disc-brake-rub-when-out-of-the-saddle#latest
  • roadrunner20roadrunner20 Posts: 40
    ibr17xvii said:

    roadrunner20 said:

    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all?

    I think personally it could be the pistons like you suggested, with regards to cleaning them can you use disc brake cleaner? (or am I going to have to go and buy a load of shimano disc brake fluid?)

    Cheers again

    Plenty of good stuff on this thread I posted on the very same topic:

    https://forum.bikeradar.com/discussion/13107944/disc-brake-rub-when-out-of-the-saddle#latest
    I'm tempted to say it's a canyon issue. Sinse bike arrived the rotors were bent in transit which wasn't great start and reckon pistons not aligned properly.

    Going to have a play today and see what's going on.

    Regarding the rub, when I get out of saddle on climbs it also apparent which is why I originally thought something was wrong as out of saddle climbs the bike isn't moving side to side as much as sprints where one might expect disc rub.

    Either way it's all very annoying especially given the nature of the aeroad being a sprint bike...
  • ibr17xviiibr17xvii Posts: 1,065
    roadrunner20 said:

    ibr17xvii said:

    roadrunner20 said:

    Cheers for the advice, so just to clarify when sprinting or climbing should discs rub at all?

    I think personally it could be the pistons like you suggested, with regards to cleaning them can you use disc brake cleaner? (or am I going to have to go and buy a load of shimano disc brake fluid?)

    Cheers again

    Plenty of good stuff on this thread I posted on the very same topic:

    https://forum.bikeradar.com/discussion/13107944/disc-brake-rub-when-out-of-the-saddle#latest
    I'm tempted to say it's a canyon issue. Sinse bike arrived the rotors were bent in transit which wasn't great start and reckon pistons not aligned properly.

    Going to have a play today and see what's going on.

    Regarding the rub, when I get out of saddle on climbs it also apparent which is why I originally thought something was wrong as out of saddle climbs the bike isn't moving side to side as much as sprints where one might expect disc rub.

    Either way it's all very annoying especially given the nature of the aeroad being a sprint bike...
    As I said in the thread it was basically every time I got out of the saddle & "threw" the bike side to side I would get rub.

    Not sure it's exclusively a Canyon issue though although maybe their frames are ever so slightly more flexy than others? Who knows.

    Either way it's deffo fixable so you don't have to just put up with it.
  • roadrunner20roadrunner20 Posts: 40
    Cheers all for replies.

    I and its a big.... Think fixed it. Slight rubbing still but marked improvement.

    Solution seemed to be a full clean of pistons along with resetting them and re centering front brake a good few times lol.

    Typically I've fixed this and now got a horrible creak coming from what seems like bottom bracket.... Sigh the tribulations of a fancy bike owner.
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